Remove string from QStringList if string value is part of other string

Question

I want to remove a string from a QStringList (folders in the code below) if it is included in another string from the same list.

Example: "/tmp/a /tmp/b /tmp/a/aa /tmp/c /tmp/a/aa/aaa /tmp/d"

I want to remove the first and third string as they are included in the fifth. I know how to do it with grep in bash, but how would I do it with Qt?

void MainWindow::on_toolButtonSourceFolders_clicked()
{
    QString startDir = lineEditStartFolder->text();
    QFileDialog* folderDialog = new QFileDialog(this);
    folderDialog->setDirectory(lineEditStartFolder->text());
    folderDialog->setFileMode(QFileDialog::Directory);
    folderDialog->setOption(QFileDialog::DontUseNativeDialog, true);
    folderDialog->setOption(QFileDialog::ShowDirsOnly, true);
    folderDialog->setOption(QFileDialog::DontResolveSymlinks, true);
    QListView *folderList = folderDialog->findChild<QListView*>("listView");
    if (folderList) {
        folderList->setSelectionMode(QAbstractItemView::MultiSelection);
    }
    QTreeView *folderTree = folderDialog->findChild<QTreeView*>();
    if (folderTree) {
        folderTree->setSelectionMode(QAbstractItemView::MultiSelection);
    }

    folderDialog->exec();
    QStringList folders = folderDialog->selectedFiles();
    if (!folders.isEmpty())
            listWidget->addItems(folders);
}

The complete code is available at https://github.com/FluxFlux/qdir2mod

Answer 1

As indicated in the comments, since the maximum number of directories is 20, I would not bother optimizing the algorithm, hence I would just go with the simplest:

QStringList folders = folderDialog->selectedFiles();
QStringList outputFolders = folders;
foreach (const QString &folder, folders) {
    foreach (const QString &f, folders) {
        if (f.contains(folder))
            outputFolders.removeOne(folder);
    }
}

You could also avoid the temporary copy, but then again, it would make the code more complex which is not worth for 20 "folders".

Also, please note that "folder" is a GUI term. What you are referring to is files and directories which is more universal. It is better to use the proper term and not get stuck with GUI terms, only.

Answer 2

With a slight modification I've solved the problem:

QStringList folders = folderDialog->selectedFiles();
QStringList outputFolders = folders;
foreach (const QString &folder, folders) {
    foreach (const QString &f, folders) {
        const QString &cfolder = (folder + "/");
        if (f.contains(cfolder))
            outputFolders.removeOne(folder);
    }
}
if (!outputFolders.isEmpty())
        listWidget->addItems(outputFolders);